Stencil



STENCIL Filed Jan. 11,1934

m, H. KAVAMMMH ,954,672

Patented Apr. 10, 1934 UNITED STATES PATENT OFFICE This invention relates to a stencil adapted to be superposed on a surface to be ornamented by sand blasting, the surface being that of a body of any material capable of being abraded and cut into by a sand blast directed against portions thereof not protected by a stencil, so that a design determined by the configuration of the -stencil may be produced. Examples of material capable of being thus abraded are stone,

such as marble or granite, glass, wood, sheet or plate metal coated with a metal of a contrasting color, portions of the coating being removable by blasting, and leather artificially colored on one side, portions of the coloring being removable by blasting.

The chief object of the invention is to provide a relatively inexpensive stencil having a. resiliently yielding continuous external surface of material resistant to a sand blast, and adapted to '20 conform closelyD to a surface to be ornamented,

and to be removably secured thereto, and leave the surface in condition to be readily cleaned after removal of the stencil.

Another object is to provide a stencil characterized by a degree of flexibility permitting its close conformation to a rough or irregular surface to be ornamented.

Another object is to provide a stencil including a sheet-like reticulated core of relatively inex" tensible material adapted to maintain the predetermined area of the stencil, and resiliently yielding enveloping material resistant to a. sand blast, enveloping the core and covering all portions thereof, including the margins of the openings therein, and presenting an inner surface adapted to be removably secured to a surface to be ornamented.

Another object is to provide a stencil including a reticulated core and enveloping resilient material resistant to a sand blast, the core being composed of fibrous strands, lines or veins crossing and interengaged as in lace having relatively large openings, so that ordinary relatively inexpensive commercial iibrous lace which is obtainable in many forms or designs may be utilized in the manufacture of the stencil, the stencil` formed by the core and enveloping material being limp or inert so that the margins of the stencil openings are adapted to resist a sand blast and conform accurately to either a smooth or a rough surface on which the stencil is super-- posed.

Other objects will hereinafter appear. i Of the accompanying drawing forming a part of this specification,-

Figure 1 is a side view of a portion of a reticulated stencil core composed of lace.

Figure 2 is an enlarged section on line 2-2 of Figure 1, showing the enveloping material.

Figure 2a is a view similar to Figure 2 show- 60 ing a skin coating on the enveloping material.

Figure 3 shows in section a portion of the stencil, and a portion of a body on which it is superposed, the body being as it appears before the sand blasting. l

Figure 4 is a view similar to Figure 3 showing the body as it appears after the sand blasting.

Figure 5 is a view similar to Figure 3 showing a rough surfaced body.

Figure 6 is a sectional view showing the body shown by Figure 5 as it appears after the sand blasting. i

Figure 7 is a perspective sectional view showing a portion of a sand blasted body.

Figure 8 is a prespective view showing a temporary coating of slow drying cementitious material such as rubber cement applied tothe inner side of the stencil, and a backing layer on said coating.

Figure 9 is a section on line 9-9 of Figure 8.

Figure 10 is a fragmentary perspective view showing a much enlarged portion of one of the strands, each filament of which has a protecting surface of. resiliently yielding material.

Figures 11, 12 and 13 are views showing an alternative construction of the stencil.

The `same reference characters indicate the same parts in all of the figures.

My improved stencil is adapted to be supported on va surface to be ornamented bysand blasting, the surface being that'of a bodyv 20 which may be of any material-capable of being abraded and cut away by the well known action ofv a' sand blast.

The stencil is designated as a whole by 21 in Figures 3, 4 and 5, and is formed to cover portions of the body surface, and has openings exposing other portions thereof.

The stencil in each of the forms hereinafter described is characterized by a resiliently yielding continuous external surface material 26 resistant to a sand blast, and conforming to said openings, and adapted to be releasably secured to a surface of the body 20. The material 26 may be a preparation of rubber latex which may contain a curing agent of well known character to give the desired qualities to the residue of rubber on drying.

The latex may contain as much as forty per cent of rubber, and be thinned down by the addition of more or less Water so that the basis is an aqueous dispersion of rubber.

In commercial latex the rubber content is commonly from thirty-three to thirty-eight per cent. by wr ight.

It is usually desirable to secure the stencil, before the sand blasting operation, to the surface to be ornaniented, to prevent accidental displacement of the stencil from its predetermined position. This may be effected by a film 30 of a slow drying soluble cementitiou's material such as rubber cement, or glue, applied to the inner surface of the stencil, the'material being capable of remaining soft and tacky for a long period, so that the stencil may be readily stripped from the surface after it has performed its function. The solubility of said material enables the residuum of the film left on the ornamented surface to be readily removed by alcohol or other solvent of the film material.

To so condition the stencil when provided with the fihn 30, that a plurality of stencils may be assembled for storage and shipment without adhesion to each other, a non-adhesive -backing layer 32, preferably of paper, may be applied to the film 30 to cover it and prevent its adhesion to any surface. The slow drying nature of the film material permits the stripping of the backing layer` '32 from the stencil, the stripping operation splitting the film so that a portion of it designated by 31 in Figure 9, remains on the stencil and causes adhesion thereof to the surface to be ornamented. I have found that the backing layer may be thusl removed several months after its application to the film, leaving the'lm portion 3l sufficiently tacky. The stencil thus conditioned constitutes an article of manufacture adapted to be stored and transported, the backing layer being removable by the user to prepare the stencil for use.

The core 25 shown by Figure 1 is composedof flexible fibrous strands fabricated to form a netlike sheet which may have the usual characteristics of ordinary lace, and is limp or inert. The intersecting strands de'ne openings whose form and arrangement determines the `ornamentation imparted to the body 20 by a sand blast.

The filaments composing the strands of the core may be independently protected by sand blast resisting material before fabrication, as indicated by Figure 10, which shows, much enlarged, a portion of one of the strands composed of assembled fibrous filaments 33 each having a protecting surface 26 of sand blast resisting material characterized as hereinbefore stated. The protecting surfaces of the several filaments collectively protect the stencil. The fabrication of the independently protected filaments results in the production of a stencil including a flexible reticulate core, and resiliently yielding protecting material resistant to a sand blast and forming the external surfaces of the stencil, including the margins of the openings defined by the reticulations.

The core may be made wholly of strands of sand blast resisting material, such as latex, interwoven to 'form a reticulated sheet. Each strand or vein may be composed of a plurality of all latex filaments 36 as indicated by Figure 11, which shows, much enlarged, a portion of a strand resembling that shown by Figure 10, excepting that the fibrous cores 33 are omitted. Figures 12 and 13 show, much enlarged, a portion of a reticulated'net-like sheet of simple form, composed of interwoven all latex strands or veins 37. After the fabrication of the al1-latex strands, the surfaces of the stencil may be additionally protected by an additional coating of latex, or other sand blast resistant'inaterial.

In each of the described embodiments of the invention including those shown by Figures 10, 11, 12 and 13, the stencil is composed of flexible strands or veins fabricated to form a reticulate or net-like flexible sheet, and resiliently yielding protecting material resistant to a sand blast, and forming the external surfaces of the stencil, said protecting material being either an integral portion of the stencil, as shown by Figures l0 to 13, or a coating enveloping a previously fabricated core as shown by Figures l, 2 and 3, said core being composed of filaments of fibrous material or fine wire, so that the core has a greater tensile strength than the protecting material.

When the core is composed of wire filaments fabricated to form a reticulate lace-like sheet, the gauge of the wire should be such that the core is desirably flexible although not limp or inert like commercial fibrous lace. The protecting material 26 is adherent to fabricated wire.

When the stencil having a fibrous lace-like core is to be used on a smooth surface to be ornamented, said surface being either fiat or curved, it is desirable to stiften the core so that it will be parallel with and conform clos"ely to said surface without having waves or undulations liable to separate portions of the stencil from the surface. The core may be stiffened in any suitable manner as by coating it with a stiffening composition such as glue, hardened on the core. The fibrous structure of the core permits it to retain glue or other stiffening material, so that the thickness of the stencil is not objectionably increased.

It is obvious that the stencil characterized as described may be used in ornamenting a surface by paint sprayed or brushed on the stencil.

Figures 4, 6 and 7 show the pits or depressions formed in the body 20 by a sand blast acting through the stencil openings 23, these openings being bounded by portions of the protecting material 26, so that no portions of the core are exposed.

It will be seen that a stencil which includes a lace core has marked advantages in that many desirable lace designs are obtainable at small cost, and special designs can be readily fabricated. The complete stencil including a lace core and a coating characterized as stated can be made at a relatively small expense, has sufcient durability to enable it to be used for a considerable number of operations, and is limp or inert so 130 that the margins of its openings are adapted to conform accurately to either a smooth surface as shown by Figures 3 and-4, or a rough surface as shown by Figure 5, the last mentioned surface being, for example, that formed by splitting 135 a block of stone.

Although I have specified latex as the sand blast resistant material, I am not limited thereto, and may employ any other suitable coating material capable of imparting the described characteristics to the stencil.

Thebody to be ornamented may be laminated wood, such as ply wood, the laminations of which are differently colored, so that the walls of the pits formed in the body by the sand blast will show portions of the differently colored layers.

A sheet or platey of relatively hard metal having a thin metallic surfacing layer contrasting llO in color with the plate, may be ornamented by removing `portions of the surfacing layer by the conjoint action of the stencil and a sand blast.

It is obvious that the surface to be ornamented may be provided with a thin coating of rubber cement or latex before the application of the stencil thereto, to cause temporary adhesion of the stencil to said surface, the coating being so thin that it will be disintegrated by the sand blast at the commencement of the operation.

In each of the described embodiments of the invention the strands or veins of the stencil are adapted to contact so closely with the portions of the surface to be ornamented that when said surface is polished, as in stainless steel, porcelain, glass, and many stone articles, the polish under the lines or Veins of the stencil is not affected by the sand blast.

A stencil made in accordance with my invention may be provided with a skin coating 27, (Fig. ure 2a) of quick drying Varnish which, when dried, is hardv and non-adhesive and slightly stiffens the stencil, and enables a plurality of stencils to be put up in a roll for storage and shipment. The varnish coating also enables thestencil to be easily handled.

The backing 32 (Figures 8 and 9) may be of paper sufficiently thin and friable to be disintegrated by a sand blast, and may therefore be allowed to remain on the stencil when vthe lat-- tel.` islplaced on the Asurface to be ornamented. The thin paper backing helps to hold a lace stencil fabric in shape, so that it may be easily handled, and may be put up inrolls like wall paper, or in single flat sheets placed one on another. The user of the stencil may apply a film of either glue or rubber cement to the surface to be ornamented.

If desired vthe backing layer may be double and includea vsecond outer layer 40 shown by dott-ed lines in Figure 9, temporarily secured by a suitable adhesive to the outer surface of the layer 32, the exposed side of the layer `l0 being nonadhesive, and the adhesion securing the layer 40 being of such nature that said layer may be removed in preparing the stencil for use.

This application is a continuation in part, of

my prior application entitled Stencils for sand blasting filed January 25, 1933, Serial No. 653,412.

I claim:

1. A stencil composed of flexible strands or veins fabricated to form a reticulate or net-like sheet, and resiliently yielding protecting material resistant to a sand blast and forming the external surfaces of the stencil, including the margns of the openings defined by the reticulations thereof.

v2. A stencil composed of Vflexible strands or veins fabricated to form a reticulate or net-like flexible sheet, and resiliently yielding protecting material resistant to a sand blast and forming the external surfaces of the stencil including the margins of the openings defined by the reticulations thereof, the protected strands or veins being normally limp or inert, so that the margins of the stencil openings are adapted to conform accurately to either'a smooth or a rough surface on which the stencil is superposed.

3. A stencil composed of flexible strands or veins fabricated to form a reticulate 'or net-like flexible sheet, and resiliently yielding protecting material resistant to a sand blast and forming the external surfaces of the stencil including the margins of the openings defined by the reticulations thereof, each of the strands being composed of a plurality of assembled core fllaments of superior tensile strength each having a protecting surface of resiliently yielding material, the filaments being asembled to form said strands, the protecting surfaces of the filaments collectively protecting the strands.

4. A stencil including a flexible core composed of flexible strands or veins fabricated to form a reticulate or net-like flexible sheet, and resiliently yielding protecting material resistant to al sand blast and forming the external surfaces of the stencil including the margins of the openings defined by the reticulations thereof, the strands flexible sheet, resiliently yielding protecting material resistant to a sand blast, and a skin coating of hard drying varnish covering said protecting material.

7. As an article of manufacture, a stencil including flexible strands or veins fabricated to form a reticulate or net-like flexible sheet, and

resiliently yielding protect-ing material resistant to a sand blast and forming the external surfaces of the stencil including the margins of the openings defined by the reticulations thereof, said stencil being prepared for storage and shipment and for temporary adhesion to a surface to be ornamented, by a. film of slow drying cementitious material applied to its inner surface, and a non-adhesive backing layer covering the film andseparably secured to the stencil thereby, the separation of said layer from the stencil splitting said film and leaving a portion thereof lexposed on the stencil to temporarily secure it to a'surface on which it is superposed.

8. A stencil as specified by claim 1, said protecting material being an aqueous dispersion of rubber.

9. A stencil as specified by claim 1, said core being a sheet of textile lace.

10. A stencil as specied by claim 1, said core being a reticulate sheet of woven wire of a gauge permitting fabrication into a flexible sheet closely resembling fibrous lace.

11. A stencil as specified by claim 1, the reticulate sheet being provided with a skin ofhard drying material.

12. A stencil including a reticulate sheet composed of wire strands, and resiliently yielding protecting material resistant to a sand blast covering the wire strands.

ROBERT H. KAVANAUGH. 

